I hate it when people start fights at parties; always wonder why people have to get worked up over petty bullshit when people are trying to drink, smoke and have a good time in general. If this happened at one of my parties, his ass would be tossed out and told to never come back again. There is absolutely no room, at least in my house, for people who cause trouble and get the cops called; thereby inconveniencing the party host who has to hide illegal stuff and deal with their bullshit.